Logic circuit made of biomaterials such as protein films

Abstract

A logic circuit has the first electron transmission protein film made of the first electron transmission protein, the second electron transmission protein made of the second electron transmission protein having a redox potential different from that of the first electron transmission protein and glued on top of the first electron transmission film, the third electron transmission protein made of the third electron transmission protein having a redox potential different from that of the second electron transmission protein and glued on top of the second electron transmission protein film, an electrode connected to the first electron transmission protein film, an electrode having an electrical influence on the second electron transmission protein film, and an electrode connected to the third electron transmission protein film to form transistors making use of differences in redox potential among the respective electron transmission proteins for performing a logical operation for a plurality of inputs.

What is claimed is: 
     
       1. A logic circuit having an output terminal and at least one input terminal, which comprises: a first electron transmission protein film made of a first electron transmission protein;   a second electron transmission protein film made of a second electron transmission protein having a redox potential different from that of said first electron transmission protein and joined on top of said first electron transmission protein film;   a third electron transmission protein film made of a third electron transmission protein having a redox potential different from that of said second electron transmission protein and joined on top of said second electron transmission protein film;   a source electrode connected to said first electron transmission protein film;   a gate electrode having an electrical influence on said second electron transmission protein film;   a drain electrode connected to said third electron transmission protein film;   said first, second, and third electron transmission films being coupled so as to form a driving transistor network in which a series connection of at least one circuit group consisting of at least one transistor with its drain and source connected in parallel to a pair of common drain and source terminals;   said common drain terminal of the first circuit group in said series connection being connected to said output terminal;   said common source terminal of the last circuit group in said series connection being connected to a second power supply having a potential lower than that of said first power supply;   the gate of said transistor in said circuit group being connected to said input terminal;   said load transistor and said driving transistor network being of the same type; and   threshold voltages of said load and driving transistor network being substantially the same.   
     
     
       2. A logic circuit according to claim 1, wherein the numbers of said input terminal, said transistor, and said circuit group are one so that it functions as an inverter amplifier. 
     
     
       3. A logic circuit according to claim 1, wherein said first and third electron transmission protein films are made of a flavodoxin electron transmission protein. 
     
     
       4. A logic circuit according to claim 1, wherein said second electron transmission protein film is made of a cytochrome electron transmission protein. 
     
     
       5. A logic circuit according to claim 1, wherein said output is given by ##EQU2## wherein + and * mean the logical sum and the logical product, respectively, and I11 through I1i, I21 through I2j, and Il1 through Ilk are respective signals put into said input terminals. 
     
     
       6. A logic circuit according to claim 1, wherein said transistor is made of at least two kinds of electron transmission proteins having different redox potentials.